Implants of this kind are known from DE 44 23 527 A1 and serve as replacements for vertebrae or vertebral parts ablated from the spinal column. The implants make possible a distraction of the spinal column region containing the implant by twisting the center part of the implant. Each of the two end parts of the implant can be connected with the center implant part by its own screw thread, whereby the two threads are arranged coaxially in the longitudinal direction of the spinal column and run in opposite directions with respect to each other. If desired, through the openings in the implant parts it is possible to introduce a material to be put inside tubular elements, such as bone cement or bone fragments, to achieve a quicker attachment of the implant. Therefore the implant is well suited for the induction of bone formation and stimulation of bone growth and after implantation can grow easily and quickly into the bone. In any case in these implants the total axial length is at least equal to the total length of two oppositely working threads, which is a limitation of the minimal implant length, so that these known implants can not be used as intervertebral spacers or as intervertebral disk replacements.